1. Field of the Invention
The invention relates to a jumper with a housing for bridging at least two electrical modular terminals which are located next to one another, the modular terminals each having at least one busbar and at least one opening being formed in each of the busbars. In addition, the invention relates to a structural unit comprising at least two electrical modular terminals located next to one another and a jumper which has a housing, the modular terminals each having a terminal housing made of insulating material, with at least two terminal elements located in it and at least one busbar, and in each of the terminal housings at least one functional slot being made for at least partially accommodating the jumper and at least one opening being made in the busbars.
2. Description of Related Art
Electrical modular terminals have been known for decades and are used in the millions in the wiring of electrical systems and devices. The terminals are generally locked onto support rails which for their part are often located in a plurality in the switching cabinet. The terminal elements in modular terminals are mainly screw-type terminals or tension spring terminals. In addition however insulation piercing connecting devices or leg spring terminals can also be used.
The basic type of modular terminal is the connecting terminal which has at least two terminal elements which are electrically connected to one another via an electrically conductive connecting rail, the busbar. In addition to this basic type, which is often called a feed-through terminal, there is a host of different modular terminal types which are matched especially to the respective application. Examples are protective-conductor terminals, isolating terminals and test terminals.
In particular, for modular terminals which are used in current transformer measurement circuits in power generation and distribution, various switching, isolating and testing tasks must often be performed. They include the bridging of adjacent modular terminals using plug-in jumpers which are plugged into the terminal housings and with which two or more adjacent modular terminals can be short circuited. For example, a current transformer short circuit can thus be implemented in a current transformer measurement circuit.
One such plug-in jumper is disclosed, for example, in German Patent DE 44 11 306 C1. The plug-in jumper consists of two jumper rail sections which are located parallel to one another and which each have a rail strip and a plurality of contact legs which are connected to the rail strip. In the known plug-in jumper, the spring forces of the contact legs, upon plugging into the openings in the busbars of the modular terminals and during contact-making, are aligned parallel to the lengthwise direction of the rail strip so that locking between the plug-in jumper and the busbar can be easily achieved.
Moreover, jumpers are known from practice which are arranged to be able to move in the terminal housings of adjacent modular terminals (CLIPLINE 2007 catalog, page 104, of Phoenix Contact GmbH & Co. KG). The jumpers have at least two contact regions which are connected to one another in an electrically conductive manner and which, in the contact position, can be connected to the busbar by a screw which has been screwed into the busbar of the modular terminal. The disadvantage here is that the jumper can be used only in special modular terminals in which, on the one hand, a threaded hole is made in the busbar for the screw, and on the other hand, the busbar is made such that, in general, a screw which is accessible from the outside can be screwed into the busbar, i.e., the busbar or a section of the busbar must run near the top of the terminal housing.